鬣蜥亚目（Iguania）是有鳞目的一个亚目（过去曾是蜥蜴亚目的一个下目），包含：鬣蜥、变色龙、飞蜥、以及安乐蜥与角蜥等新世界蜥蜴。

Iguania is a suborder of Squamata (snakes and lizards) that contains the iguanas, chameleons, agamids, and New World lizards, such as anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, Iguania is believed to form the sister group to the remainder of the Squamata. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. Iguanians are largely arboreal and have primitively fleshy, nonprehensile tongues, although the condition is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic (the oldest known member is Bharatagama, which lived about 190 million years ago in what is now India), and currently includes these extant families: